How would you handle this situation with a close friend?

Required background: This is a friend that I have had for short of ten years.. We were very close at one point, when he moved away and got married things changed but we still kept in contact, had amazing conversations and know so much of each other’s history. We trusted each other implicitly and shared much of the same interests and understood one anothers sense of humor.

Well there is this issue that he doesn’t like talking about and that was a problem between us in the past. It continues to be a problem for him in a very real way, in his current circumstances. We end up talking around the elephant inferring and so forth. I am always cautious not to push too hard and let him open up when he so chooses.

Finally, in the midst of the conversation I got frustrated and told him it was OK to talk about the problem. I wasn’t judging him, I accepted him a long time ago. He got off the phone extremely quickly after and while we are still on some of each other’s networks he says he is busy when I tried to chat him up twice. He hasn’t posted anything or sent anything to me or tried to call.

This happened months ago. While we don’t communicate every day or week we’ve almost always kept the lines open. So I miss him.

For Instance: Oh…. would be interested in this.
I wonder what thoughts… on this.
I wonder how… is doing.
... is the only person who I feel comfortable sharing… with.

I recognize that people grow apart over time and some people are temporary. I am not convinced this is the case in the situation. I don’t know how to approach him so he won’t shut down. My intention was to make conversations more comfortable and offer acceptance that he didn’t get elsewhere.

What should I do? What would you do?